Five (8%) of the 61 cyst preparations were positive for the 148 bp-tpi amplicon only, implying assemblage A for these G. intestinalis cysts, and 31 (51%) were positive for the 81-bp tpi amplicon only, implying assemblage B. The remaining 25 samples (41%) were positive for both tpi gene amplicons, indicating the presence of a mixed population of these two assemblages (Table 1). This evidence concerns the gene TPI1 and cyst.